This list is from ECF, it is by no means complete.
List made by my4jewels, alphabetizing by Stosh.
All of the ejuice/flavors listed below have been reported by an ecf member to cause problems for them. YMMV.
Some of these are premixed juices, some are flavorings that DIY'ers use. Contributions have been made by myself and other members. So far we have:
Here is the list so far. Everything listed here has caused someone a problem with a polycarbonate tank. Some have reported no issues whatsoever with some of these juices/flavorings. Use at your own risk with polycarbonate tanks.
Alien Vision Cravelope
Alien Vision Pineapple Pulp
Cinnamon like "atomic cinnamon" types, not warm cinnamon like cinnamon coffee cake, this is okay
Cola(because of cinnamon)?
Decadent Vapors Bubblegum
Dekang Pina Colada/Tobacco mixed
DIY Flavorshack Tangerine
DIY Gummibear(melted plastic endcaps on DCTank).
E liquids that contain triacetin, used in vg liquids to carry flavor more effectively
Ecblends Apple Pie
Ecblends Cinnamon Apple
ECBlends Gingerbread, double flavor
Elixirliquids Cinnamon Death
Elixirliquids Deathday Cake
Elixirliquids Heaven and Hell(cinnamon with menhtol)
Elixirliquids Rage(hot cinnamon)
FA Lemon Sicily Flavoring
Fuzion Vapor Gumby's Blood
HellaVapor's Raspberry Winta-green.
***** ***** Vanilla Cola
KBV Hummingbird Nectar
Lorann Butter Rum flavor
Lorann Peppermint oil
Mad Murdock's Radiator Pluid
MadVapes Black Licorice
Mimosa(because of the orange)
Mountain Oak Vapors Red Drop
Mrs. T's Kickin' Pineapple Mrs. T's Snickerdoodle
Mrs. T's Strawberry Lemonade
Mrs. T's Strawberry Shortcake
Mt. Baker Vapor Arnold Palmer
Mt. Baker Vapor Marachino Cherry
Mt. Baker Vapor says not to use their Amaretto, Cinnamon, Citrus flavors, Mt. Dew, Sweet Tarts, Green Apple, Ginger, and Lavender in plastic tanks
Mt. Dew flavoring
Mt. Vapor's Lemonade(endcaps melted)
My Vape Store Cinnabun
Neon Vapors neon Cherry
Oil based/e liquid that conains essential oils, when mixed with.pg/vg, creates esters which will crack plastics
Rawrvapor Hawaii Sunrise
Tasty Vapor Atomic Cinnicide
Tasty Vapor Cherry Cola
Tasty Vapor Sherbet
Timmy's Double Double from Juicy Clear
TPA Blueberry Candy(melted plastic endcaps on DCTank)
TPA Blueberry(melted plastic endcaps on DCTank)
TPA Cherry Blossom flavoring
TPA Cinnamon Danish flavoring
TPA Earl Gray Tea flavoring
TPA Honeysuckle flavoring
TPA Lemon Lime flavoring
TPA Maraschino Cherry flavoring
TPA Pineapple flavoring
TPA Ripe Banana flavoring
TPA Rootbeer Flavoring
TPA RY4 Double Flavoring
TPA Spearmint flavoring
TPA Vanilla Bean Ice Cream flavoring
TPA Vanilla Custard flavoring
V4L WOW Peppermint Nobacco
Vapalicious Gooey Butter Cake.
Vape Dude's Lemonade
Vapor Renu Mt. Dew Baha Blast and Strawberry Limeade
Vapor Renu Teaberry, Cherry Vanilla (possibly most of their flavors)
Vaporbomb Fire 'n Ice(cracked tank, melted rubber drip tip)
Vaporbomb Green Apple
Vaporbomb Hot Cinnamon Candy
Vaporbomb Sun Kissed
Vaporbomb Sweet Cherry
Vaporbomb Sweet Cinnamon Red Hots
Vapor Room Cinnamon Red Hots
Virgin Vapor Luscious Lime
Virgin Vapor Sweet Summer Lemonade
Vixen Vapor RH Candy Cane
Vixen Vapor Rootbeer
Wintergreen juice or flavoring
Perfumer's Apprentice lists triactetin as in ingredient in some of their flavors, so be sure to check that out. Triacetin has caused problems for many members.
Disclaimer: These are not "bad" juices. They just have the potential to cause cracking in tank systems using polycarbonate tubing.